Microwave-assisted synthesis of transition metal phosphide

Abstract

A method of synthesizing transition metal phosphide. In one embodiment, the method has the steps of preparing a transition metal lignosulfonate, mixing the transition metal lignosulfonate with phosphoric acid to form a mixture, and subjecting the mixture to a microwave radiation for a duration of time effective to obtain a transition metal phosphide.

What is claimed is: 
     
       1. A method of synthesizing transition metal phosphide, comprising the steps of:
 (a) preparing a mixture consisting of a salt of lignin, a transition metal salt, phosphoric acid, silica, and carbon black; and 
 (b) subjecting the mixture to a microwave radiation for a duration of time effective such that the mixture is smoking and sparkling, thereby reducing phosphorus having a positive oxidation state of the phosphorus acid to phosphorus having a negative oxidation state, and forming a transition metal phosphide nanoparticle using the phosphorus from the phosphorus acid and the transition metal from the transition metal lignosulfonate, 
 wherein the transition metal comprises one of Cu, Fe, Ga, Mo, Co, Zn, Zr and Ti; and 
 wherein the preparing and the reducing are executed without adding a reducing gas or an inert gas. 
 
     
     
       2. The method of  claim 1 , wherein the salt of lignin comprises sodium salt of lignin. 
     
     
       3. The method of  claim 1 , wherein the transition metal salt comprises transition metal chloride. 
     
     
       4. The method of  claim 1 , wherein the frequency of the microwave radiation is about 2.45 GHz. 
     
     
       5. The method of  claim 1 , wherein the transition metal-phosphide coexists with carbon to form a carbon composite. 
     
     
       6. A method of synthesizing transition metal phosphide, comprising the steps of:
 (a) preparing a mixture consisting of a salt of lignin, a transition metal salt, and phosphoric acid; and 
 (b) subjecting the mixture to a microwave radiation for a duration of time effective such that the mixture is smoking and sparkling, thereby reducing phosphorus having a positive oxidation state of the phosphorus acid to phosphorus having a negative oxidation state, and forming a transition metal phosphide nanoparticle using the phosphorus from the phosphorus acid and the transition metal from the transition metal lignosulfonate, 
 wherein the transition metal comprises one of Cu, Fe, Ga, and Mo. 
 
     
     
       7. The method of  claim 6 , wherein the salt of lignin comprises sodium salt of lignin. 
     
     
       8. The method of  claim 6 , wherein the transition metal salt comprises a transition metal chloride. 
     
     
       9. The method of  claim 6 , wherein the frequency of the microwave radiation is about 2.45 GHz. 
     
     
       10. The method of  claim 6 , wherein the transition metal phosphide is in the form of nano-spheres.